The present invention relates generally to locking mechanisms and, more particularly, to an electronic locking mechanism adaptable to fit enclosures of varying dimensions, while maintaining minimal power consumption.
There are currently many different ways to lock things. One of the most common ways is the key locking mechanism. This type of mechanism is relatively secure and tamper proof. However, it is difficult to re-key a key lock to work with a different key if the original key is lost or stolen. Key locks can also be picked. In addition, it is sometimes inconvenient to keep a key.
Manual and electronic combination locking mechanisms provide many advantages. People may forget the combination, but at least they do not have to keep a key. The problem with manual combination locks such as those found on safes, vaults, lockers, and other enclosures, however, is that parts of the actual locking mechanism are often exposed and thus subject to tampering. In addition, mechanical combination locks require machining to high tolerances to avoid manipulation attacks.
While electronic combination locks are generally not exposed, they have other disadvantages. Electronic locks must keep the strike retracted until the user opens the lock, thus using large amounts of power. Another problem associated with electronic locks is that the strike operation can time out, thus forcing re-entry of the key. If one-time keys are used, access can be denied if the user is slow.
Another disadvantage of both key and combination locking mechanisms is their inability to accommodate enclosures of varying dimensions without having to alter the basic operation of the locking mechanism or having to use multiple locks for long doors.
Therefore, there is a need for an electronic locking mechanism that draws little power and that is adaptable to accommodate a broad range of enclosures.
One embodiment of the present invention provides an improved electronic locking mechanism that requires little power during operation and that is readily adaptable to fit enclosures of varying sizes without having to change the operation of the locking mechanism. The locking mechanism may be adapted to use two rods, a first and a second. The first rod may be attached to one side (i.e., a fixed portion) of an enclosure. The second rod may be attached to the door or lid (i.e., a movable) side of the enclosure. The first and second rod can be cut to the length necessary to fit the enclosure. Attached to one of the rods, preferably the second rod, are one or more cam wafers which are configured to engage to the first rod to lock the mechanism.
The locking mechanism itself is solenoid driven and can be secured to any one of the cam wafers in order to hold the lock in place. The solenoid is spring actuated and is powered by a battery or some other source of electricity. In the preferred embodiment, the electricity source is located in a module external from the locking mechanism. When the correct combination code is entered through a keypad and electronic controller, the controller energizes the solenoid just long enough for the solenoid to lift the pawl arm. When the pawl arm is lifted, no other force acts on the cam wafer in the locking mechanism. Because of the action of a torsion spring, which is coiled around the second rod with potential energy, when the force of the pawl arm is released from the cam wafer the second rod rotates and the cam wafer rotates and disengages from the first rod.
To lock the mechanism, the user manually pushes on the door or lid of the enclosure. The first rod contacts the cam wafer and, as the user pushes the door or lid shut, the second rod rotates and the cam wafer rotates. An aperture in the cam wafer slips behind a portion of the pawl arm, which comes down like a clamp and locks it in place.